2 hours and 35 minutes. According to Baidu map, the drive from Mianyang to Nanchong is about 200. 1 km, which takes 2 hours and 35 minutes and passes through Mianxing East Road and Torch North Road. Mianyang, known as Mianzhou in ancient times, is a prefecture-level city, a second-class big city and a provincial sub-central city under the jurisdiction of Sichuan Province.